1. Field of the Invention
This invention relates generally to a self-adhesive laminate and a method for using the laminate to seal around windows, doors, roofing, roof flashing and in other construction environments, and a method of constructing the laminate.
2. Description of the Related Art
In building construction generally, there are many areas of the building in which two materials do not seal perfectly. Even if materials seal well when installed, it is known that buildings settle and, with extremes in temperatures and humidity, buildings expand and contract. When these occur, two contacting materials will separate. Separation in materials that are designed to keep out air, moisture and pests can lead to inefficiency, damage and infestation.
In particular, prefabricated windows are supplied with a metal or polymer flange along their perimeter. This flange is typically nailed or screwed to the building sheathing, such as oriented strand board (OSB), during installation of the window in a rough opening formed in the wall for the window. The finish siding is applied over the sheathing and the flange, and commonly abuts a protruding portion of the window.
The flange is not typically sealed against the sheathing in a water-tight manner, and therefore wind-driven rain can leak around the flange. Leaks can be prevented if a tape is applied to seal the joint between the flange and sheathing before the finish siding is applied. Such tapes attach to at least part of the width of the flange, bridging over any gap between the flange and sheathing, and attaching to the sheathing. The laminate's adhesive forms a seal along the entire outer perimeter of the flange and along the sheathing directly adjacent the flange, thereby providing the water-tight seal needed to prevent inefficiency, damage and pest infestation.
Various types of adhesive tapes or laminates have been used to seal these flanges, and these laminates generally include a polyethylene or polyester film adhered to a bitumen layer, which is commonly rubberized asphalt. Such tapes and related materials are described in U.S. Pat. No. 4,936,938 to Simpson et al.; U.S. Pat. No. 5,096,759 to Simpson et al.; U.S. Pat. No. 5,142,837 to Simpson et al.; U.S. Pat. No. 6,103,356 to Messenger; U.S. Pat. No. 6,627,017 to Simpson; and U.S. Pat. No. 6,479,119 to Simpson. The foregoing patents are incorporated herein by reference.
Although the laminates discussed in the foregoing patents are advantageous over previous technology, they have some disadvantages under extreme conditions. For example, the bitumen layer that is self-sealing around fasteners that penetrate the laminate also has acceptable adhesive properties at temperatures greater than 60 degrees Fahrenheit. Thus, such bitumen layers provide the adhesion to window flanges and sheathing under optimal conditions. However, construction work often must be performed when temperatures fall to as low as 20 degrees Fahrenheit. Conventional laminates may not adhere acceptably in such circumstances, especially when the surfaces to which laminates must adhere have non-ideal textures to which adhesives do not readily adhere even under ideal temperature conditions. Because OSB is made with a waxy coating that provides release from forming molds, it is often difficult to adhere to OSB, even in warm weather.
Two types of adhesives are typically used on flashings for windows and doors: rubber modified asphalt and butyl rubber. A disadvantage of rubberized asphalts is that they have a relatively high temperature (such as 50 degrees F.) below which they lose sufficient adhesion. Butyl rubber adhesives retain their adhesive characteristics at lower temperatures, but are relatively expensive compared to asphalt based adhesives. Typically butyl rubber layers are not thick enough to provide nail-sealing capabilities without being prohibitively expensive.
The present invention solves these and other problems present in the prior art by providing a number of features. These features result in the present invention being a significant improvement over the prior art.